With the increasing demands of today's economy, it is necessary for manufacturers to deliver their products to consumers in an efficient manner. To meet these demands, manufacturers often ship large quantities of packaged products to wholesalers and distributors which, in turn, transport smaller quantities of these packaged products to local retailers and dealers In the initial stages of the shipping system, packaged products are often stored in a manufacturer's warehouse and thereafter loaded onto trailer trucks for transportation to a desired location.
For years, conventional pallets have been the work horses of the shipping industry. These pallets, which are essentially platforms upon which goods are placed for storage and transportation, are fabricated from a variety of materials and, for decades, have been particularly effective in moving large quantities of products from one location to another. Wood is probably the most common material used to construct shipping pallets. Of course, other types of pallet materials have also been employed by those in the transportation industry as substitutes for the conventional wooden pallets. The evolution of these other types of pallets has been due, at least in part, to the limited useful life of wooden pallets as well as the increasing costs of wood in recent years. Alternative, less costly materials which have been used for fabricating pallets include plastics as well as metal.
Pull sheet pallets, for example, have been developed as a replacement to conventional wooden pallets for the purpose of transporting cargo from one location to another. In general, a pull sheet pallet is a sheet of material, such as polypropylene or high density polyethylene, which has a high tensile strength. A pull sheet pallet is placed upon a floor of a warehouse or truck so that cargo can be loaded onto it. The pull sheet pallet may incorporate a lip which projects upwardly and outwardly in order that a gripper bar of a motorized vehicle can grasp the lip and pull the pull sheet pallet onto a platen of the vehicle. Some in the transportation industry consider the pull sheet pallet to be an effective substitute for conventional pallets for various reasons. First, pull sheet pallets are relatively inexpensive. Second, these pull sheet pallets are not nearly as bulky as conventional pallets because they may only be millimeters thick. Thus, pull sheet pallets are light weight and compact for storage. Third, although pull sheet pallets occasionally tear, they are far more durable than conventional pallets.
One type of pull sheet pallet is disclosed in U.S. Pat. No. 5,226,372 to Frenkel. This pull sheet pallet, fabricated of a plastic material such as polypropylene and high density polyethylene, has a plurality of nubs projecting from a lower surface thereof and a plurality of corresponding recesses formed into an upper surface thereof. The plastic material is stiff yet resilient so that when cargo is placed on the upper surface of the pallet and thereafter transported, shock may be absorbed by minute contractions and subsequent expansions of the nibs. Frenkel's pull sheet pallet also incorporates a lip which may be grasped by the gripper bar of the motorized lift vehicle so that the loaded pull sheet pallet can be pulled onto a platform.
In an effort to optimize storage capacity in warehouses, manufacturers often stack multiple tiers of palletized cargo on top of another. Each of these tiers of palletized cargo consists, essentially, of a base pallet, of either the wood, plastic or metal type, upon which the packaged products are supported for storage. Typically these packaged products are in the form of individually boxed products, several products packaged in a large container, or bags. With these stacked arrangements, the cargo associated with a lower tier of the palletized products is required to directly support an upper tier of palletized cargo. Thus, the lower cargo is placed in direct contact with the pallet associated with the upper tier. Depending upon the condition of the upper pallet and the weight of its load, the cargo associated with the lower pallet can become permanently damaged. Moreover, even when the stacked or tiered pallets are stationary relative to the other, damage can be exacerbated when the pallets are transported by a conventional forklift. Damage can also arise when the stacked cargo is transported in moving rail cars. Not only can the mere shifting of the upper palletized cargo cause excessive wear on the cargo located therebelow, but splintering of the upper pallet can puncture the lower cargo.
In an effort to alleviate the potential damage resulting from conventional shipping techniques, the transportation industry has been known to employ pallet separator sheets which are interposed between the multiple tiers of palletized cargo. Such a separator sheet typically has a lower surface which spans across and is in contact with the lower cargo and an opposite upper surface which is in direct contact with the pallet associated with the upper tier of palletized cargo. These pallet separator sheets are typically constructed of fiber, corrugate or plywood However, while these sheets may be suitable to add protection from dust, moisture and spillage, they are not well suited to provide a durable covering which is adapted to protect against the potential problems discussed above.
Accordingly, there is a need in the transportation industry to provide a new and useful pallet separator sheet which is adapted to be placed between tiers of palletized cargo to allow for storage and transportation of the tiers with a reduced risk of damage to the cargo. The present invention accomplishes this objective, among others by modifying the construction of known slip sheet pallets to provide a device which is uniquely suitable for use as a pallet sheet separator.